Field of the Invention
The present invention relates to a sheet supporting apparatus for supporting a sheet, and an image forming apparatus equipped with the sheet supporting apparatus.
Description of the Related Art
Hitherto, as disclosed in Japanese Unexamined Patent Application Publication No. 2015-74504, an image forming apparatus equipped with a storage cassette including a tray for supporting a sheet and a pair of side regulation members for regulating a width direction position of the sheet supported on the tray is known. The tray has a width direction length corresponding to a dimension of a maximum supportable size of the sheet on the tray, and a cutout is formed on the tray such that an end portion of the sheet having a minimum supportable size can be regulated by the side regulation member.
The side regulation member includes a loading limit index that indicates an upper limit of the sheets capable of being supported on the tray, and an auxiliary supporting portion provided immediately under the loading limit index and configured to support the sheets. The auxiliary supporting portion is formed to have approximately the same height as an upper face of the tray, and an end portion in the width direction of the sheet supported on the tray is supported from below by the auxiliary supporting portion. Thereby, the sheets can be suppressed from being sagged down into the cutout formed on the tray, and the sheets can be prevented from being loaded beyond the loading limit index.
However, the auxiliary supporting portion disclosed in Japanese Unexamined Patent Application Publication No. 2015-74504 merely extends slightly in the width direction, and for example, if a sheet having a large width-direction size is supported on the tray, the sheet may still be sagged down into the cutout even if the sheet is supported by the tray and the auxiliary supporting portion. In that case, a gap is formed between the loading limit index and the uppermost surface of the sheets, and the sheets may be overloaded, according to which sheet feeding failure such as folding or jamming of the sheet may occur.
Further, if the auxiliary supporting portion is configured to be extended greatly in the width direction, it becomes necessary to form a cutout independently on the tray so that the tray does not interfere with the auxiliary supporting portion, and the strength of the tray is weakened thereby. If the strength of the tray is weakened, the sheets cannot be stably positioned at the sheet feed position especially in a state where the tray supporting a full load of sheets is lifted, and sheet feeding failure may occur.